As a passenger I have always marveled at the spiraling departure often used to avoid sfo air traffic when departing ksjcI have attempted to use the fmc to fly this Loupe dep in the 747. to no avail, the fmc cannot seem to understand the spiral nature of the climb and simply flys direct to the fourth waypoint, something norcal dep would not be to happy with Im sure. However the sid in the fmc legs does seem to spell it out fairly well.I realize that 747 do not depart from SJC. I wonder how the 737 pilots would handle and or program this dep. Is the fmc of use in this situation and how so?I am interested to hear the discussion on this both pdmg and real world aspectsI have included links to the two dep panelsThanksMikehttp://204.108.4.16/d-tpp/0602/00693LOUPE.PDFhttp://204.108.4.16/d-tpp/0602/00693LOUPE_C.PDFksjc link:http://www.airnav.com/airport/KSJC

I don't think the FMC is used for this departure, at least for the first parts like "1.8 DME TURN RIGHT 120 MAINTAIN 5000". Flying this many times on SW I know that the turn comes very quickly. Although I am not 100% I think they simply set 5000 on the MCP (Reset for each cleared altitude thence) put a range arc on the ND for 1.8 and engage LNAV after the 120 right turn. Well I would put a range ring =P.................Randy J. Smith................A PROUD MEMBER OF THE PMDG BETA TEAM[h4]Evolution is a process that results in heritable changes in a population spread over many generations[/h4]

Agreed. I believe this is a vectored departure after the 120. I'm sure this is to deconflict with KSFO traffic on the PYE1 or BSR2 arrivals, with KSFO 28's active. The Loupe appears to turn departing traffic south for the climb while the arriving KSFO traffic descends north of KSJC.....I could be wrong though. It's happend before!

Thanks for the thoughts. THey are as much as I would have envisioned.My follow up is; How would a pilot in the real world utilize the fmc in this situation? would they program the full route including the loupe dep prior to takeoff as usual but not enage lnav or vnav until the loop has been completed and the plane has past the airport for the second time? Do you have to be sure to overfly the early waypoints on your own effort? ( or they will remain in the fmc legs page )ThanksMike

I would figure that the first fix in the SID is the SJC VOR. If you read the textual description, it says:"Climb runway heading at SJC 1.8 DME northwest of SJC VOR/DME turn right heading 120, maintain 5000, for radar vectors to SJC VOR/DME, then via SJC R-339 to DYBLO INT, Thence...."Climb the runway heading, at 1.8DME right to 120 and to 5000 ft., ATC will then vector to SJC VOR. In other words, until you get to the SJC VOR, you'd be using the MCP for heading/ALT control. When ATC clears you to the SJC VOR, go DIR to the VOR and let the FMC navigate from there.As I mentioned before, I assume the right 120 is to deconflict with arriving KSFO traffic on the 28's, allowing you time to climb over that arriving traffic.

That makes perfect senseThank Youfor refernce here is the sidSID LOUPE1 FIX RONRE AT OR ABOVE 14000 FIX DYBLO RNW 29 TRK 304 UNTIL 461 FIX OVERFLY SJC02 TRK 120 UNTIL RADIAL 47 FROM NAVAID SJC FIX SJC AT OR ABOVE 12000 RNW 30L TRK 304 UNTIL 461 FIX OVERFLY SJC02 TRK 120 UNTIL RADIAL 47 FROM NAVAID SJC FIX SJC AT OR ABOVE 12000